In an implantable hearing aid system, transducers within the middle ear engage an auditory element and transduce between electrical signals and mechanical vibrations. Middle ear hearing aid systems are not as susceptible to mechanical feedback as other types of systems. Such systems are more comfortable for the patient than other types of hearing aids, such as those placed directly in the external auditory canal. Transducers which contact an auditory element, such as one of the elements of the ossicular chain, require precise and reliable disposition within the middle ear. This is further complicated by anatomical variations among patients.